In current cellular wireless systems, the uplink power provided from the base station to each mobile phone is controlled to provide an acceptable signal-to-interference-plus noise ratio to the mobile phone while minimizing the transmit power levels from the base station of the cellular tower. Some cellular wireless systems allow several users of mobile phones to communicate over a common channel. Each user of the shared channel creates interference for the other users of the channel. Such wireless systems use power control to limit the interference.
If the power level transmitted by the mobile phone is minimized, the interference is minimized for the mobile phone while maintaining the signal integrity. Systems which use the lowest transmitter power at the base stations and the mobile phone meet the minimum signal-to-interference-plus noise ratio constraint and maximize the number of channels. Additionally, users of the mobile phones obtain the maximum talk time from the battery powered mobile phones and the base station minimizes wasted excessive power when the lowest transmitter power is used by the base station. As the number of users on the system changes, the minimum signal-to-interference-plus noise ratio changes and the system must be dynamically monitored to maintain the minimum signal-to-interference-plus noise ratio for the system.
Currently, the base stations are controlled by a centralized distribution node controller, such as a mobile service switching center (MSC) that regulates the power level of all the signals transmitted from several base stations. The mobile phones are mobile nodes located within range of wireless signals emitted to and from the base stations. The distribution nodes in the wireless network are controlled by a centralized distribution node controller, such as a mobile service switching center (MSC) that regulates the power level of all the signals transmitted from the distribution nodes to receiver nodes.
Communication between the centralized distribution node controller and the distribution nodes for the mobile phone adds infrastructure, latency and network vulnerability. The latency is due to averaging received signals at the centralized distribution node controller, processing the averaged signals at the centralized distribution node controller, and transmitting signals between the centralized distribution node controller and the distribution nodes. The resulting time delays are in the range of about 10 ms to about 100 ms.
In some cases, it is necessary or desirable to set up a remote wireless communication network that is not in communication with a centralized distribution node controller. For example, the military establishes a joint tactical radio system (JTRS) including a distribution node to establish communication between soldiers operating within range of the JTRS. The soldiers carry wireless transceivers which function as the nodes within the JTRS. In an exemplary case, the JTRS is based within a group of mobile vehicles and the distribution node is a larger transceiver in one of the vehicles.
In another example, a small town in remote regions, such as remote parts of China or Alaska, establishes a wireless communication network for the people living in the remote region without the infrastructure of a centralized distribution node controller to reduce the total system cost. In both of these latter systems, there is no central controller to equalize and/or minimize the transmitted power level from the distribution node.
By distributing the power control from a centralized distribution node controller to the distribution nodes for the mobile phone, the infrastructure and the system latency are reduced. For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need for wireless network systems, including mobile wireless network systems, that efficiently regulate the power distributed from distribution nodes without using a centralized distribution node controller.